dial

a plate, disk, face, or other surface containing markings or figures upon which the time of day is indicated by hands, pointers, or shadows, as of a clock or sundial.

2.

a plate or disk with markings or figures for indicating or registering some measurement or number, as of pressure, number of revolutions, the frequency to which a radio is tuned, etc., usually by means of a pointer.

3.

a rotatable plate, disk, or knob used for regulating a mechanism, making and breaking electrical connections, etc., as in tuning a radio or television station in or out.

4.

Also called rotary dial. a rotatable plate or disk on a telephone, fitted with finger holes that are marked with letters or numbers, used in making calls through an automatic switchboard.

5.

any mechanism on the face of a telephone by which the caller places a call, as push buttons.

6.

Also called miner's dial. Mining. a compass used for underground surveying.

dial

The word perhaps was abstracted from a phrase such as Medieval Latin rota dialis "daily wheel," and evolved to mean any round plate over which something rotates. Telephone sense is from 1879, which led to dial tone (1921), "the signal to begin dialing," which term soon might be the sole relic of the rotary phone.

v.

1650s, "to work with aid of a dial or compass," from dial (n.). Telephone sense is from 1923. Related: Dialed; dialing.

for the measurement of time, only once mentioned in the Bible, erected by Ahaz (2 Kings 20:11; Isa. 38:8). The Hebrew word (ma'aloth) is rendered "steps" in Ex. 20:26, 1 Kings 10:19, and "degrees" in 2 Kings 20:9, 10, 11. The _ma'aloth_ was probably stairs on which the shadow of a column or obelisk placed on the top fell. The shadow would cover a greater or smaller number of steps, according as the sun was low or high. Probably the sun-dial was a Babylonian invention. Daniel at Babylon (Dan. 3:6) is the first to make mention of the "hour."